<s>
Linux	B-Application
Pluggable	B-Application
Authentication	I-Application
Modules	I-Application
(	O
PAM	O
)	O
is	O
a	O
suite	O
of	O
libraries	O
that	O
allows	O
a	O
Linux	B-Application
system	B-Application
administrator	I-Application
to	O
configure	O
methods	O
to	O
authenticate	O
users	O
.	O
</s>
<s>
There	O
are	O
Linux	B-Application
PAM	I-Application
libraries	O
allowing	O
authentication	O
using	O
methods	O
such	O
as	O
local	O
passwords	O
,	O
LDAP	B-Protocol
,	O
or	O
fingerprint	O
readers	O
.	O
</s>
<s>
Linux	B-Application
PAM	I-Application
is	O
evolved	O
from	O
the	O
Unix	B-Application
Pluggable	B-Application
Authentication	I-Application
Modules	I-Application
architecture	O
.	O
</s>
<s>
Linux-PAM	O
separates	O
the	O
tasks	O
of	O
authentication	O
into	O
four	O
independent	O
management	O
groups	O
:	O
</s>
<s>
They	O
may	O
also	O
pass	O
authentication	O
information	O
on	O
to	O
other	O
systems	O
like	O
a	O
keyring	B-General_Concept
.	O
</s>
